Quote:
Originally posted by Cheekmonkey
As too the triple calibration, we don't even use three calibration points doing simple analytical chemistry in school.
|
That's surprising. The pH monitor in the biochem lab I worked in during college always used 3-point calibration. Probes are not linear, so a 3rd point is needed to more accurately calculate their response curve.
I can take two new probes with my ACIII, calibrate them (letting each probe settle for 10 minutes before storing the data points), and the probes will often differ by .05 unit or more when placed in the same SW. That just shouldn't happen when trying to monitor pH, and I believe if they used 3-point calibration it could be eliminated.
I bought some pH 9 cal fluid to use for the high point, this should give more accurate readings. (At least ACIIIs let you choose the low/high cal fluid values, which is nice.)